Simulation systems are frequently employed to train operators of vehicles, especially pilots of aircraft, in various simulated combat exercises in which a warfare theatre and various forces are modeled. One particularly effective system for providing such simulation to one or more trainees linked by a distributed network is shown in U.S. published patent application 2009/0099824 A1 of Falash et al., published on Apr. 16, 2009, and entitled DISTRIBUTED PHYSICS BASED TRAINING SYSTEM AND METHODS, which is herein incorporated by reference in its entirety.
The interactions of such a simulation may be very complicated and take place at very high speeds. Modeling such highly-complex entity interactions with high precision is challenging in distributed training simulations, and modeling a high speed missile and its interaction with an aircraft target is particularly difficult. Missiles and aircraft can close together hundreds of feet in a fraction of a second, which can present a problem even in a purely localized group of simulators, and becomes much more difficult in a more geographically-distributed system where there is also a problem of latency, i.e., communication delays caused by the distance between the simulators and the lag of the interlinking network.
Even with rapid processing frame times and manageable network latencies, an error in position between a missile detonation and the aircraft target is likely to occur in distributed simulations. Very slight positional errors introduced by latency and jitter can cause missile models to fail. Even when the distance errors are in the tens of feet, the missile's small warhead and an inexact target aircraft location can produce significant inaccuracies when calculating the effect of detonation effects or the occurrence of weapon impacts.
One approach is statistics-based and it assumes damage based only on missile proximity at the time of detonation (assuming it can be accurately interpreted by the simulation) and a pre-determined probability of kill (Pk) for the missile. For example, the Pk value might be such that if a missile passes within twenty meters of a target aircraft, there is a 95% chance that the aircraft is destroyed.
In the existing protocols and standards, most weapons effects are resolved by this proximity-based Pk and “a roll of the dice” (or random number generation or other computer randomness/probability resolution method). That approach typically does not factor the exact aspect, geometry, aircraft material strength, and missile warhead capability at the time of detonation. Also, latency between simulations and jitter may degrade these models in higher-fidelity systems.
In lower-fidelity models, the Pk may not rely on detonation distance, or may be very insensitive to distance. In those systems, or in a distributed simulation that encounters lost data packets and network delays, the simulated missile sends data to the effect that any detonation is a direct impact, i.e., a “zero” value miss distance. The simulator host computer system of the targeted vehicle can then accept or reject the “kill” based on its own data of the interaction. Most host computer systems in the targeted aircraft try to calculate the perceived miss distance independently, and to then use a localized statistical approach. Others may just automatically accept the “kill” and destroy the targeted aircraft 100% of the time. This mismatch between systems can lead to confusion as to whether a missile was truly effective or not.
Other systems increase the kill distance of the warhead to compensate for any latency or network issues, sometimes up to thousands of feet, with an obvious loss of accuracy in the simulation.
Significant training issues can arise from these two approaches to missile warhead modeling. The pilot in a high-fidelity flight simulator might have maneuvered or reacted to a missile effectively, but was nonetheless killed by a bad roll of the dice or a poorly implemented kill decision in the simulation system. Being on the unlucky side of the roll of the dice that gets one's ownship destroyed often leaves the trainee who was hit by the missile with questions like “why did it kill me?”, “how close was it?”, and “how could I have better survived?” It also becomes impossible to tell the pilot how to improve his counter-missile defensive tactics if the feedback from the results of the engagement appears random.
In addition, new weapon systems have advanced beyond the mechanical type of projectile to include lasers and other energy-based weapons. The difficulty of assessing effectiveness in a simulation of a directed energy weapon, e.g., a laser system, may be even more complex than determining missile effectiveness, due to the even higher speed of the damage delivery and the longer duration of interaction with the target.
These overall difficulties with the prior art simulation systems result in the accuracy of the simulation and fair fight parameters of the training being reduced, and the inability to accurately determine effectiveness of a missile or a directed energy weapon against a target makes training in defensive strategies very difficult or impossible.